Solder joints such as ball-grid array (BGA) and bump interconnects are often employed to mechanically and electrically join microelectronic devices during microelectronic packaging such as integrated circuit (IC) packaging. These solder joints may fail when placed under mechanical stresses such as shock, vibration, or drop tests compromising the reliability of microelectronic packages. The most common drop test failure mechanism occurs at weaker defect-rich layers that are created during the soldering reaction.
Current methods to address such solder joint failure include using an underfill to provide additional structural support between the joined microelectronic devices. However, underfill requires costly additional process steps that could be circumvented with strengthened solder joints. Solutions that locally strengthen the joints between solder balls and microelectronic devices by reducing the size of weaker layers while accommodating traditional bulk solder materials for solder balls are needed in the microelectronic packaging industry to reduce solder joint reliability problems and avoid costly process development associated with new bulk solder materials for solder balls.